Cool Diagrams - What software is being used here?

Question

I've seen some cool, nifty data diagrams done on some blogs/articles and have been wondering what software they were using to render these diagrams, e.g. MS Visio? For example, what is used on this blog to create those colorful diagrams towards the middle of the article under "Definition Providers": http://www.thecodejunkie.com/2009/05/introduction-to-mef-programming-models.html?

I find these diagrams very appealing...

[EDIT - Addition]: I run across these diagrams all over the place, e.g. one of the bloggers I follow is Nikhil Kothari - http://www.nikhilk.net/Silverlight-Layout-Panels-1.aspx.

Answer 1

Those look pretty much like the diagrams you can generate with Word 2007 to me. Though it could have been some other software.

Answer 2

You should ask one of the authors to be sure having the right answer...

Answer 3

I'm gonna take a guess and say OmniGraffle for MacOS.